For instance, in May 1981, the newly elected president of France, François Mitterrand, accidentally left the launch codes given to him by his predecessor at home,in the suit he was wearing the day before.

In the case of President Carter, he not only left the code in his suit, the suit plus nuclear launch code found their way to:

the dry cleaner.

There is also the problem of drugs. It’s not a good idea for people who are guarding nuclear weapons to be constantly tripping balls outside of work. This has also been a problem:

In February 1974, US Senator Sam Nunn spent two weeks in Europe visiting US NATO bases. He reported that ‘there were people guarding nuclear weapons [who] were hooked on drugs’.

Or to have people with their finger on the nuclear launch button, who only a few years ago were told by a British psychiatrists that they are so mentally disturbed they are not mentally fit to stand in court, as was the case of Pakistan’s former president Zardari. (this is my addition)

You can read the entire report, entitled ‘Too Close for Comfort: Cases of Near Nuclear Use and Options for Policy’, by Patricia Lewis, Heather Williams, Benoît Pelopidas and Sasan Aghlani, April 2014, Chatham House, here. Page 14 lists all the 13 nuclear near misses.